Magnetic beads have several advantages over alternate non-magnetic bead technologies, and are thus finding increasing application in all areas of life-sciences research and development including drug discovery, biomedicine, bioassay development, diagnostics, genomics and proteomics.
This is attributed to the numerous advantages of magnetic beads including ease of use; rapid experimental protocols; the amenability and convenience for high-throughput automated and miniaturized processing such as high-throughput screening; and the potential for scalability due to the availability of large homogenous biomagnetic separation equipment. You will find much more information about this topic in our protein purification handbook.
The beads may be functionalized with biomolecules (e.g. proteins or nucleic acids) or chemically derivatized to obtain various functional groups that enable a diverse range of applications. Several different types of magnetic beads are currently available; however, not all magnetic beads are created equally.
Current microsphere technologies (magnetic and non-magnetic) use solid or semi-porous/cracked microspheres which limit binding capacity for target molecules to the surface of the polymer beads. The novel microsphere technology platform, ReSyn®, comprising a hyper-porous polymer matrix, allows penetration of biological and synthetic molecules throughout the volume of the beads, as opposed to limited surface-based binding of conventional bead technologies. The technology allows for high capacity without compromising the speed of magnetic separation, as opposed to attempts to increase capacity by reducing particle size (increasing surface area), where slower bioseparation unfortunately leads to increased protocol times.
As an example, custom MagReSyn® Streptavidin MAX microspheres (www.resynbio.com) offer exceptional binding capacities of >12 mg.ml-1 (1.2 mg.mg-1 support) biotinylated IgG and >120 000 pmoles.ml-1 (12 000 pmoles.mg-1 support) biotinylated oligo. The exceptional surface area for binding of molecules makes hyper-porous polymer magnetic beads a competitive alternative to slower non-magnetic techniques in applications where volumetric capacity (low microsphere content or concentrated sample preparation) is important. The capacity of a microsphere technology is an important consideration for your potential application, since it may lead to a significant cost-reduction as fewer magnetic microspheres, and less reagent, are required.
A schematic representation of solid, cracked/porous and hyper-porous ReSyn® technology.
You will find this post and many more interesting articles about using biomagnetic separation for protein purification in our Advanced Guide to Biomagnetic Protein Purification:
- The 3 most important considerations in designing magnetic particles
- Advantages of Magnetic Agarose in Protein Purification
- Key benefits of Magnetic Sepharose beads
Author: Dr. Isak Gerber, CTO at ReSyn Biosciences, Gauteng, South Africa
Dr. Isak B. Gerber has a Doctorate in Biochemistry from the University of Johannesburg in South Africa, and has amassed an array of experience in protein biochemistry including method and assay development, protein production and purification. He is a co-inventor on two international patents and author on nine international peer-reviewed scientific publications. For the past four years Dr Gerber has been an integral member of the team that developed and patented a novel next-generation microsphere technology platform (ReSyn®) at the Council for Scientific and Industrial Research (CSIR, South Africa). The patented technology is currently being commercialized by a new biotech start-up enterprise, ReSyn Biosciences (Pty) Ltd (www.resynbio.com). The technology was translated into a range of superior performance magnetic microsphere products suitable for life-sciences R&D largely through the efforts of Dr Gerber. Dr Gerber currently serves as Chief Technology Officer for ReSyn Biosciences.